---
title: mapKeys
description: Map over the keys of an object
group: Object
---

## Basic usage

Given an object and a `toKey` callback function, returns a new object with all the keys
mapped through the `toKey` function. The callback is given both the key and value for each entry.

```ts
import { mapKeys } from 'radash'

const ra = {
  mode: 'god',
  power: 'sun'
}

mapKeys(ra, key => key.toUpperCase()) // => { MODE, POWER }
mapKeys(ra, (key, value) => value) // => { god: 'god', power: 'power' }
```
